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| author | Mark Brown <broonie@kernel.org> | 2022-01-24 18:57:19 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2022-02-08 17:42:59 +0300 |
| commit | 23afc82539cfcce105bf18c5c835c75e463ca349 (patch) | |
| tree | d1dff697802756d27088e4921e1a71b80949b511 /arch/arm64/kvm/fpsimd.c | |
| parent | dfd42facf1e4ada021b939b4e19c935dcdd55566 (diff) | |
| download | linux-23afc82539cfcce105bf18c5c835c75e463ca349.tar.xz | |
KVM: arm64: Add comments for context flush and sync callbacks
Add a little bit of information on where _ctxflush_fp() and _ctxsync_fp()
are called to help people unfamiliar with the code get up to speed.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220124155720.3943374-2-broonie@kernel.org
Diffstat (limited to 'arch/arm64/kvm/fpsimd.c')
| -rw-r--r-- | arch/arm64/kvm/fpsimd.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 2f48fd362a8c..397fdac75cb1 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -84,6 +84,11 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) vcpu->arch.flags |= KVM_ARM64_HOST_SVE_ENABLED; } +/* + * Called just before entering the guest once we are no longer + * preemptable. Syncs the host's TIF_FOREIGN_FPSTATE with the KVM + * mirror of the flag used by the hypervisor. + */ void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu) { if (test_thread_flag(TIF_FOREIGN_FPSTATE)) @@ -93,10 +98,11 @@ void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu) } /* - * If the guest FPSIMD state was loaded, update the host's context - * tracking data mark the CPU FPSIMD regs as dirty and belonging to vcpu - * so that they will be written back if the kernel clobbers them due to - * kernel-mode NEON before re-entry into the guest. + * Called just after exiting the guest. If the guest FPSIMD state + * was loaded, update the host's context tracking data mark the CPU + * FPSIMD regs as dirty and belonging to vcpu so that they will be + * written back if the kernel clobbers them due to kernel-mode NEON + * before re-entry into the guest. */ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) { |